/*******************************************************************************
 * Copyright (c) 2005, 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.application;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.IWorkbenchPreferenceConstants;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.WorkbenchException;
import org.eclipse.ui.actions.ActionFactory;
import org.eclipse.ui.internal.WorkbenchWindowConfigurer;
import org.eclipse.ui.internal.util.PrefUtil;
import org.eclipse.ui.intro.IIntroManager;

/**
 * Public base class for configuring a workbench window.
 * <p>
 * The workbench window advisor object is created in response to a workbench
 * window being created (one per window), and is used to configure the window.
 * </p>
 * <p>
 * An application should declare a subclass of <code>WorkbenchWindowAdvisor</code>
 * and override methods to configure workbench windows to suit the needs of the
 * particular application.
 * </p>
 * <p>
 * The following advisor methods are called at strategic points in the
 * workbench window's lifecycle (as with the workbench advisor, all occur 
 * within the dynamic scope of the call to 
 * {@link PlatformUI#createAndRunWorkbench PlatformUI.createAndRunWorkbench}):
 * <ul>
 * <li><code>preWindowOpen</code> - called as the window is being opened; 
 *  use to configure aspects of the window other than actions bars</li>
 * <li><code>postWindowRestore</code> - called after the window has been
 * recreated from a previously saved state; use to adjust the restored
 * window</li>
 * <li><code>postWindowCreate</code> -  called after the window has been created,
 * either from an initial state or from a restored state;  used to adjust the
 * window</li>
 * <li><code>openIntro</code> - called immediately before the window is opened in
 * order to create the introduction component, if any.</li>
 * <li><code>postWindowOpen</code> - called after the window has been
 * opened; use to hook window listeners, etc.</li>
 * <li><code>preWindowShellClose</code> - called when the window's shell
 * is closed by the user; use to pre-screen window closings</li>
 * </ul>
 * </p>
 * 
 * @since 1.0
 */
public class WorkbenchWindowAdvisor {

    private IWorkbenchWindowConfigurer windowConfigurer;

    /**
     * Creates a new workbench window advisor for configuring a workbench
     * window via the given workbench window configurer.
     * 
     * @param configurer an object for configuring the workbench window
     */
    public WorkbenchWindowAdvisor(IWorkbenchWindowConfigurer configurer) {
        Assert.isNotNull(configurer);
        this.windowConfigurer = configurer;
    }

    /**
     * Returns the workbench window configurer.
     * 
     * @return the workbench window configurer
     */
    protected IWorkbenchWindowConfigurer getWindowConfigurer() {
        return windowConfigurer;
    }
    
    /**
     * Performs arbitrary actions before the window is opened.
     * <p>
     * This method is called before the window's controls have been created.
     * Clients must not call this method directly (although super calls are okay).
     * The default implementation does nothing. Subclasses may override.
     * Typical clients will use the window configurer to tweak the
     * workbench window in an application-specific way; however, filling the
     * window's menu bar, tool bar, and status line must be done in 
     * {@link ActionBarAdvisor#fillActionBars}, which is called immediately
     * after this method is called.
     * </p>
     */
    public void preWindowOpen() {
        // do nothing
    }

    /**
     * Creates a new action bar advisor to configure the action bars of the window
     * via the given action bar configurer.
     * The default implementation returns a new instance of {@link ActionBarAdvisor}.
     * 
     * @param configurer the action bar configurer for the window
     * @return the action bar advisor for the window
     */
    public ActionBarAdvisor createActionBarAdvisor(IActionBarConfigurer configurer) {
        return new ActionBarAdvisor(configurer);
    }
    
    /**
     * Performs arbitrary actions after the window has been restored, 
     * but before it is opened.
     * <p>
     * This method is called after a previously-saved window has been
     * recreated. This method is not called when a new window is created from
     * scratch. This method is never called when a workbench is started for the
     * very first time, or when workbench state is not saved or restored.
     * Clients must not call this method directly (although super calls are okay).
     * The default implementation does nothing. Subclasses may override.
     * It is okay to call <code>IWorkbench.close()</code> from this method.
     * </p>
     * 
     * @exception WorkbenchException thrown if there are any errors to report
     *   from post-restoration of the window
     */
    public void postWindowRestore() throws WorkbenchException {
        // do nothing
    }

    /**
     * Opens the introduction componenet.  
     * <p>
     * Clients must not call this method directly (although super calls are okay).
     * The default implementation opens the intro in the first window provided
     * if the preference IWorkbenchPreferences.SHOW_INTRO is <code>true</code>.  If 
     * an intro is shown then this preference will be set to <code>false</code>.  
     * Subsequently, and intro will be shown only if 
     * <code>WorkbenchConfigurer.getSaveAndRestore()</code> returns 
     * <code>true</code> and the introduction was visible on last shutdown.  
     * Subclasses may override.
     * </p>
	 * @since 1.2
     */
    public void openIntro() {
        // TODO: Refactor this into an IIntroManager.openIntro(IWorkbenchWindow) call
        
        // introOpened flag needs to be global
        IWorkbenchConfigurer wbConfig = getWindowConfigurer().getWorkbenchConfigurer();
        final String key = "introOpened"; //$NON-NLS-1$
        Boolean introOpened = (Boolean) wbConfig.getData(key);
        if (introOpened != null && introOpened.booleanValue()) {
			return;
		}

        wbConfig.setData(key, Boolean.TRUE);

        boolean showIntro = PrefUtil.getAPIPreferenceStore().getBoolean(
                IWorkbenchPreferenceConstants.SHOW_INTRO);
        
        IIntroManager introManager = wbConfig.getWorkbench().getIntroManager();
        
        boolean hasIntro = introManager.hasIntro();
        boolean isNewIntroContentAvailable = introManager.isNewContentAvailable();
        
		if (hasIntro && (showIntro || isNewIntroContentAvailable)) {
			PrefUtil.getAPIPreferenceStore().setValue(
					IWorkbenchPreferenceConstants.SHOW_INTRO, false);
			PrefUtil.saveAPIPrefs();
			
            introManager
                    .showIntro(getWindowConfigurer().getWindow(), false);
        }
    }

    /**
     * Performs arbitrary actions after the window has been created (possibly 
     * after being restored), but has not yet been opened.
     * <p>
     * This method is called after the window has been created from scratch, 
     * or when it has been restored from a previously-saved window.  In the latter case,
     * this method is called after <code>postWindowRestore</code>.
     * Clients must not call this method directly (although super calls are okay).
     * The default implementation does nothing. Subclasses may override.
     * </p>
     */
    public void postWindowCreate() {
        // do nothing
    }

    /**
     * Performs arbitrary actions after the window has been opened (possibly 
     * after being restored).
     * <p>
     * This method is called after the window has been opened. This method is 
     * called after the window has been created from scratch, or when
     * it has been restored from a previously-saved window.
     * Clients must not call this method directly (although super calls are okay).
     * The default implementation does nothing. Subclasses may override.
     * </p>
     */
    public void postWindowOpen() {
        // do nothing
    }

    /**
	 * Performs arbitrary actions as the window's shell is being closed
	 * directly, and possibly veto the close.
	 * <p>
	 * This method is called from a ShellListener associated with the window,
	 * for example when the user clicks the window's close button. It is not
	 * called when the window is being closed for other reasons, such as if the
	 * user exits the workbench via the {@link ActionFactory#QUIT} action.
	 * Clients must not call this method directly (although super calls are
	 * okay). If this method returns <code>false</code>, then the user's
	 * request to close the shell is ignored. This gives the workbench advisor
	 * an opportunity to query the user and/or veto the closing of a window
	 * under some circumstances.
	 * </p>
	 * 
	 * @return <code>true</code> to allow the window to close, and
	 *         <code>false</code> to prevent the window from closing
	 * @see org.eclipse.ui.IWorkbenchWindow#close
	 * @see WorkbenchAdvisor#preShutdown()
	 */
	public boolean preWindowShellClose() {
		// do nothing, but allow the close() to proceed
		return true;
	}

    /**
	 * Performs arbitrary actions after the window is closed.
	 * <p>
	 * This method is called after the window's controls have been disposed.
	 * Clients must not call this method directly (although super calls are
	 * okay). The default implementation does nothing. Subclasses may override.
	 * </p>
	 */
    public void postWindowClose() {
        // do nothing
    }

    /**
     * Creates the contents of the window.
     * <p>
     * The default implementation adds a menu bar, a cool bar, a status line, 
     * a perspective bar, and a fast view bar.  The visibility of these controls
     * can be configured using the <code>setShow*</code> methods on
     * <code>IWorkbenchWindowConfigurer</code>.
     * </p>
     * <p>
     * Subclasses may override to define custom window contents and layout,
     * but must call <code>IWorkbenchWindowConfigurer.createPageComposite</code>.
     * </p> 
     * 
     * @param shell the window's shell
     * @see IWorkbenchWindowConfigurer#createMenuBar
     * @see IWorkbenchWindowConfigurer#createCoolBarControl
     * @see IWorkbenchWindowConfigurer#createStatusLineControl
     * @see IWorkbenchWindowConfigurer#createPageComposite
     */
    public void createWindowContents(Shell shell) {
        ((WorkbenchWindowConfigurer) getWindowConfigurer()).createDefaultContents(shell);
    }

    /**
     * Creates and returns the control to be shown when the window has no open pages.
     * If <code>null</code> is returned, the default window background is shown.
     * <p>
     * The default implementation returns <code>null</code>.
     * Subclasses may override.
     * </p>
     * 
     * @param parent the parent composite
     * @return the control or <code>null</code>
     */
    public Control createEmptyWindowContents(Composite parent) {
        return null;
    }
    
	/**
	 * Returns <code>true</code> if the given folder in the given perspective
	 * should remain visible even after all parts in it have been closed by the
	 * user. The default is <code>false</code>. The return value for a certain
	 * combination of perspective id and folder id must not change over time.
	 * 
	 * @param perspectiveId
	 *            the perspective id
	 * @param folderId
	 *            the folder id
	 * @return <code>true</code> if the given folder should be durable
	 * 
	 * @since 1.4
	 */
	public boolean isDurableFolder(String perspectiveId, String folderId) {
		return false;
	}

    /**
     * Disposes any resources allocated by this window advisor.
     * This is the last method called on this window advisor by the workbench.
     * The default implementation does nothing.
     * Subclasses may extend.
     */
    public void dispose() {
        // do nothing.
    }
	
	/**
	 * Saves arbitrary application specific state information.
	 * 
	 * @param memento the storage area for object's state
	 * @return a status object indicating whether the save was successful
	 */
	public IStatus saveState(IMemento memento) {
		// do nothing
		return Status.OK_STATUS;
	}
	
	/**
	 * Restores arbitrary application specific state information.
	 * 
	 * @param memento the storage area for object's state
	 * @return a status object indicating whether the restore was successful
	 */
	public IStatus restoreState(IMemento memento) {
		// do nothing
		return Status.OK_STATUS;
	}
}
